P0174 means system too lean (bank 2). Same lean condition as P0171, but on bank 2. When P0171 and P0174 appear together, the cause is almost always something
Drive gently and get it diagnosed within days.
Same lean condition as P0171, but on bank 2. When P0171 and P0174 appear together, the cause is almost always something affecting the whole engine — vacuum leak, MAF sensor, or fuel pressure.
Top cause, especially with both banks lean.
Affects both banks equally.
Weak pump or clogged filter.
Unmetered air.
Common on higher-mileage V6/V8s.
Typically $50–$600
MAF cleaning often under $50 DIY; gasket/leak repair typically $150–$500. Estimates vary by vehicle. Costs are estimates and vary by vehicle, location, and shop.
Safe short-term; fix within days. Both banks lean = systemic issue, usually findable.
Typically $50–$600. MAF cleaning often under $50 DIY; gasket/leak repair typically $150–$500. Estimates vary by vehicle.
Drive gently and get it diagnosed within days.
The most common cause is vacuum leak. Top cause, especially with both banks lean.